Write the differences between:
(a) Blood and Lymph
(b) Open and Closed system of circulation
(c) Systole and Diastole
(d) P-wave and T-wave
(a) Blood and lymph
Blood |
Lymph |
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1. |
Blood is a red-coloured fluid that contains RBCs. |
1. |
Lymph is a colourless fluid that lacks RBCs. |
2. |
It contains plasma, RBCs, WBCs, and platelets. It also contains proteins. |
2. |
It contains plasma and lesser number of WBCs and platelets. It lacks proteins. |
3. |
Blood transports nutrients and oxygen from one organ to another. |
3. |
Lymph plays a role in the defensive system of the body. It is a part of the immune system. |
(b) Open and closed systems of circulation
Open system of circulation |
Closed system of circulation |
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1. |
In this system, blood is pumped by the heart, through large vessels, into body cavities called sinuses. |
1. |
In this system, blood is pumped by the heart, through a closed network of vessels. |
2. |
The body tissues are in direct contact with blood. |
2. |
The body tissues are not in direct contact with blood. |
3. |
Blood flows at low pressure. Hence, it is a slower and less efficient system of circulation. |
3. |
Blood flows at high pressure. Hence, it is a faster and more efficient system of circulation. |
4. |
The flow of blood is not regulated through the tissues and organs. |
4. |
The flow of blood can be regulated by valves. |
5. |
This system is present in arthropods and molluscs. |
5. |
This system is present in annelids, echinoderms, and vertebrates. |
(c) Systole and diastole
Systole |
Diastole |
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1. |
It is the contraction of the heart chambers to drive blood into the aorta and the pulmonary artery. |
1. |
It is the relaxation of the heart chambers between two contractions. During diastole, the chambers are filled with blood. |
2. |
Systole decreases the volume of the heart chambers and forces the blood out of them. |
2. |
Diastole brings the heart chambers back into their original sizes to receive more blood. |
(d) P-wave and T-wave
P-wave |
T-wave |
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1. |
In an electrocardiogram (ECG), the P-wave indicates the activation of the SA node. |
1. |
In an electrocardiogram (ECG), the T-wave represents ventricular relaxation. |
2. |
During this phase, the impulse of contraction is generated by the SA node, causing atrial depolarisation. |
2. |
During this phase, the ventricles relax and return to their normal state. |
3. |
It is of atrial origin. |
3. |
It is of ventricular origin. |